A miter saw typically has the capacity to crosscut work pieces placed against its horizontal table and vertical fence. This saw can be rotated to make vertical cuts through a work piece at various angles relative to the fence. A vertical cut is known as a “miter cut.”
A compound miter saw has the capability to tilt the blade (counterclockwise) to an angle relative to the table, generally from 0° to 45° left of vertical. A cut made with the blade tilted at an angle (and perpendicular to the fence) is known as a “bevel cut.” A cut made with the blade set to both an angle relative to the fence (miter angle) and an angle relative to the base (bevel angle) is known as a “compound cut.”
A dual bevel compound miter saw has the added capacity to tilt the blade to an angle relative to the table generally from 45° left of vertical to 45° right of vertical. This arrangement allows for more “compound cut” variations.
A slide miter saw has the saw component mounted to a rail system allowing it to slide backward and forward thereby increasing the saw's cutting capacities. The slide mechanisms are typically added to a compound saw.
Miter saws typically include a detent system that allows the table and the attached cutting tool to be preset to specific angles relative to the fixed fence. A detent system provides an accurate means to preset and reset the saw to make the most popular cuts. A miter saw typically provides 10 to 12 preset detent positions or recesses.
The typical miter saw table includes a rotating disc-like work surface that is supported by the tools' base. The table includes a support member for a lock handle in the front and a saw mounting area to the rear, behind the fence. In addition, a spring-loaded retractable detent pin or wedge is mounted in the handle area The base typically has a rounded front shape that is concentric with its table and includes detent holes or slots positioned to accept the above-mentioned pin or wedge. The locking handle moves to create pressure against the rounded front of the base outside of the detent slot or hole locations. The lock handle may be of a rotating screw-type or lever cam-type design. In order to indicate the saw's preset cutting position, the rotating table supports a pointer that relates to an angle scale on the fixed base.
In using a detent system to preset the miter cut angle, the user would first loosen the lock handle, and retract the detent pin or insert. This would be followed by rotating the table, releasing the detent pin or insert into a desired slot or recess, and relocking the handle. Some users rely on the detent system to hold the saws' position for cutting without using the lock handle.
If a user wants to preset the miter saw for an angle cut not provided by the detent system, he would allow the spring-loaded pin or insert to rest against the front surface of the base outside of the detent slots and tighten the locking handle. For these cuts, the user must use the locking handle to hold the saw's position. Due to the interaction between the lever and the detent, however, the prior art arrangements do not allow for a fine adjustment that is near one of the predetermined detent positions.
One example of the prior art is disclosed in U.S. Pat. No. 5,337,641 (Duginske), which discloses a microadjuster mounted to a flip stop assembly on a T-shaped slot in the track of a miter saw. The microadjuster is adjustably secured to the track, such that the rotation of a bolt moves the flipstop assembly either away from or toward a work piece depending on the rotation of the bolt. The flipstop can then be locked into position on the track. As can be easily seen, the use of a microadjuster mounted on the track of a table saw limits the size of the work piece that can be used. Furthermore, a bulky microadjuster located on top of the track of the table saw makes it difficult to use with smaller table saws or miter saws.
Another example of the prior art is disclosed in U.S. Pat. No. 5,215,296 (Adams et al.). Adams et al. discloses an apparatus for mechanical positioning, and adjustments thereof, or cutting tools such as saws. The apparatus has a microadjustable carriage for use with a work piece such that the carriage rotates relative to the base and moves objects attached to it. Once the desired adjustment has been made, the carriage is secured to the base of the cutting tool using a clamp. One drawback of this type of prior art is its inability for use with table saws that have other than rectangular tops. It would be impossible to use this application on cutting tools having a circular base, such as miter saws.
A further example of the prior art, most notably that used with miter saws is a centering device that is disclosed in U.S. Pat. No. 5,425,294 (Ushiwata et al.). In a benchtop miter saw having a bevel function, a centering system can be used for a zero-tilt angle of the position of cut or for the often-used 45-degree angle of cut. The centering system has a detent lever engaging the worktable at preselected positions for changing the angle of cut. They do not, however, provide a mechanism for finely adjusting the angle of cut, such that the angle can be adjusted plus or minus a few degrees of the selected position.
As the prior art examples show, a number of disadvantages remain. First, no prior art provides a fine-adjustment mechanism for use with a cutting tool having a circular base, such as a miter saw. Those disclosing the use of a lever to position a cut fail to provide a mechanism for microadjustments. Furthermore, it is difficult to finely adjust the lever as the lever normally engages a recess in a worktable. As the lever moves within a few degrees of the recess in a worktable, the lever naturally propagates into the recess making it very difficult for microadjustments. Second, the prior art does not provide for an easy method of making a fine adjustment as most fine adjustments are bulky or must be clamped into position. Finally, the prior art microadjustment mechanisms, because of the number of parts needed to create the device, are not economically viable.
Therefore, what is needed is a fine-adjustment mechanism whereby the user can quickly and easily make slight adjustments to the angle of cut. What is further needed is a fine-adjustment mechanism that is smaller, more efficient and more economical. What is further needed is a fine-adjustment mechanism for use with a variety of saws, such as miter saws and table saws, such that the cutting tool can be quickly adjusted for a specific angle of cut.